Evaluate the feasibility of using a novel imaging test, [18F]ISO-1 PET/CT to image sigma-2 receptor binding in cancer. Correlate uptake with standard and experimental pathology assays of biopsy or surgical tissue. The target population is up to 30 adult patients at least 18 years, with a known or suspected breast cancer and at least one lesion 1.0 cm in size by at least one type of standard imaging.